On June 13, Mike Dyas (32), in company with other cavers, was rappeling the 100 foot entrance drop into Crookshank Cave, Greenbrier County, West Virginia. As he rappeled it became apparent that the free end of the rope had tangled on a ledge when thrown down during rigging. When noticed, the tangle was about ten feet from Dyas. He jerked it loose, dislodging two rocks of about ten and three pounds. Dyas dodged the larger, but was struck on the helmet by the smaller. Dyas suffered no injury and so continued.
NSS News, May 1981 (Part 2) V39N5, Page A11-12
Editor "Another Turtle Club Member" D.C. Speleograph 32:9 Sept. 1976 p.18
The initial caver down a drop must expect this sort of hazard. The caver should not have descended below the tangle before dealing with it. A good helmet, in this case a Bell Toptex, is an obvious asset.